The 6DE7 is a double triode with dissimilar sections designed for use in television receivers.
Triode one is designed for use as a frame timebase oscillator, and triode two was designed to be used as a vertical deflection amplifier.
The basic valve came in three heater versions. 6DE&, 10DE7 and 13DE7. The first would be suited to equipment with mains transformers, whereas the 600 and 450 mA versions have defined warm-up times and would be used on series heater chains in domestic equipment.
The amplifier triode has a heat radiating fin at the top of the grid supports.
The anodes are quite similar.
The amplifier triode anode seen face on.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 57 mm tall.
Reference: Data-sheet. Type 6DE7 was first introduced in 1957. See also1957 adverts.